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llvm-svn: 267847

1 files changed, 12 insertions, 0 deletions

diff --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp
index 7799a7030b9..6d9b2509f6b 100644
--- a/lld/ELF/Writer.cpp
+++ b/lld/ELF/Writer.cpp
@@ -741,6 +741,18 @@ void Writer<ELFT>::scanRelocs(InputSectionBase<ELFT> &C, ArrayRef<RelTy> Rels) {
 }
 
 template <class ELFT> void Writer<ELFT>::scanRelocs(InputSection<ELFT> &C) {
+  // Scan all relocations. Each relocation goes through a series
+  // of tests to determine if it needs special treatment, such as
+  // creating GOT, PLT, copy relocations, etc.
+  //
+  // The current code is a bit wasteful because it scans relocations
+  // in non-SHF_ALLOC sections. Such sections are never mapped to
+  // memory at runtime. Debug section is an example. Relocations in
+  // non-alloc sections are much easier to handle because it will
+  // never need complex treatement such as GOT or PLT (because at
+  // runtime no one refers them). We probably should skip non-alloc
+  // sections here and directly handle non-alloc relocations in
+  // writeTo function.
   for (const Elf_Shdr *RelSec : C.RelocSections)
     scanRelocs(C, *RelSec);
 }